Vacuum neutralization of



Jan. 12, 1954 A. c. STONEMAN VACUUM NEUTRALIZATION OF DETERGENTS 2 Sheets-Sheet l HEAT EXCHANGE? Original Filed June l2 1950 EJ ECTOR Iii g5 NEUTRALIZEB RECEIVER WEIGH TA NKS l/ Jan. 12, 1954 A. c. sToNEMAN VACUUM NEUTRALIZATION OF DETERGENTE 2 Sheets-Sheet 2 INVENTOR.

Original Filed June 12.

Reissued Jan. 12, 1954 VACUUM NEUTRALIZATION OF DETERGEN'IS Alan C. Stoneman, San Marino, Calif., assignor to Purex Corporation, Ltd., South Gate, Calif., a corporation of California Original No. 2,613,218, dated October 7, 1952, Se-

rial N0. 167,642, .lune 12,

1950. Application for reissue July 17, 1953, Serial No. 368,850

13 Claims. (Cl. 252-138) Matter enclosed in heavy brackets l: appears in reissue specification; matter printed in italics indicates This invention relates generally to improved methods for the production of organic compounds suitable for use as detergents, and particularly the alkali metal salts of organic sulfonates and sulfates, which have desirable detergent properties.

In many of its major aspects the invention is concerned primarily with a novel and highly advantageous method for eifecting neutralization of a sulfonated or sulfated stock, all in a manner facilitating and benefiting not only the neutralization stage itself, but also resulting in the production of a detergent salt, the properties and condition of which permit further processing, as in a final spray drying stage, to give a superior quality commercial product.

At the outset it may be mentioned that the invention contemplates the use or processing of any suitable organic sulfonates or sulfates, or mixtures thereof, the molecular structures of which following alkali metal neutralization, display detergent properties. Since various classes of such compounds are well known, it will suffice to indicate generally their types and structures. Broadly, such compounds may be regarded as organic sulfatos or sulfonates containing an aliphatic or alicyclic part which may or may not be attached to an aromatic ring, with the aliphatic or alicyclic part being derived from compounds containing 8 to 18 carbon atoms and capable of either direct reaction to the sulfates or sulfonates, or indirect reaction by combination with an aromatic ring which in turn is capable of reaction to an organic sulfate or organic sulfonate. Examples of such reactive alkyl radicalcontaining compounds are found in the 8 to 18 carbon olefms, alcohols, fatty acids, alkyl halides, and esters in the aliphatic or alicyclic series. The sulfonic and sulfuric acid derivatives of these compounds may be designated in the following groups: (l) Organic compounds of the general formula E OSOz-Oi-l, wherein R is an aliphatic or alicyclic containing 8 to 18 carbon atoms. Examples of this class are n-dodecyl hydrogen sulfate, n-tetradecyl hydrogen sulfate, noctadecyl hydrogen sulfate, undecane-Z-hydrogen sulfate, tridecane-l-hydrogen sulfate, and

pentadecane-/i-hydrogen sulfate in which the 8 to 18 carbon alkyl radical is derived from the sulfonation of vegetable oil fatty alcohols, or in general mixtures in which the 8 to 18 carbon alkyl radical is derived from aliphatic or alicyclic compounds of either straight or branched, symmetrical or non-symmetrical structure, such as may be found (like the compounds referred to in the the original patent but forms no part of this the additions made by reissue.

following) in distilled petroleum fractions or in other naturally occurring substances. (2) Organic compounds of the general formula R/-OSOz-OH, wherein R is any benzoid hydrocarbon radical having two or more nuclear replaceable hydrogen atoms (as derived from benzene, toluene, Xylene, phenol) and at least one nuclear hydrogen atom replaced by an aliphatic or alicyclic radical containing 8 to 18 carbon atoms. Examples of this class are dodecane-lbenzene hydrogen sulfate, heXadecane-l-benzene hydrogen sulfate, undecane-l-benzyl hydrogen sulfate, dodecane-Z-benzyl hydrogen sulfate, dodecane-Z-benzene hydrogen sulfate, or in general mixtures in which the 8 to 18 carbon alkyl radical is derived from aliphatic or alicyclic compounds of either straight or branched, symmetrical or non-symmetrical structure. (3) Organic compounds of the general formula R"-SO2-Ol-I, wherein R, is an aliphatic or alicyclio radical containing 8 to 18 carbon atoms. Examples of this class are dodecane-l-sulfonic acid, undecane-Z-sulfonic acid, heXadecane-S-sulfonic acid, or in general mixtures in which the 8 to 18 carbon alkyl radical is derived from aliphatic or alicyclic compounds of either straight or branched, symmetrical or non-symmetrical structure. (4) Organic compounds of the general formula Rm-SOz-OH, wherein R" is any benzenoid hydrocarbon radical having two or more replaceable nuclear hydrogen atoms (as derived from benzene, toluene, Xylene), and at least one nuclear hydrogen atom replaced by an aliphatic or alicyclic radical containing 8 to 18 carbon atoms. Examples of this class are the aryl substituted alkanes described in Lewis Patents No. 2,477,382 and No. 2,477,383. Other examples are n-dodecyl benzene sulfonic acid, n-dodecyl toluene sulfonic acid, undecane-Z-benzene sulfonic acid, undecane-l-benzyl sulfonic acid, trdecane- Z-benzyl sulfonic acid, or in general mixtures in which the 8 to 18 carbon alkyl radical is derived from aliphatic or alicyclic compounds of either straight or branched, symmetrical or non-symmetrical structure.

Since, as indicated, the present invention is concerned primarily with the neutralization stage, and steps beyond, it will be understood that any suitable organic sulfonates or sulfates, or mixtures thereof, included in the designated class and derived or produced in any appropriate manner, may constitute thefeed stock for neutralization to alkali metal salts having detergent properties.

With respect now to neutralization, the invention is particularly concerned with the formation of a neutralized product, or slurry, in which the recoverable salt is characterized by its light color and freedom from vaporizable impurities, and the slurry by a controllable consistency and viscosity making it superior for spray drying with additives, to a desirably high density commercial product. It has been foundthat-the temperature of neutralization, reaction rates, admixture of the reactants and simplicity in the overall neutralization operation, are obtainable by conducting the neutralization of an aqueous solution of the reactants under low pressures and temperatures maintained within a range that is found to have a significant relation to the most desirable qualities of the neutralization product.

In accordance with the invention, provision is made for contacting and intimately admixing the acid sulfonated or sulfated hydrocarbon stock with a suitable alkaline lneutralizing solution, preferably alkali metal hydroxide solution, under conditions eecting such completeness and intimacy of contact as will promote complete reaction to the point of neutralization and formation of the detergent alkali metal salt. Of critical importance is the maintenance of the reactants under low temperature conditions assuring stabilization of the desired molecular structure of the salt, and at low pressure resulting in the freeing of volatiles from the material, all to the end that the p-roduct will be of high quality with respect to color and freedom from excessive contaminants. Of further importance in relation to nal drying of a neutralized slurry, if the formation and maintenance of the slurry during neutralization, under low pressure and temperature conditions Within particular ranges that have been found to result in desirably high density of the finished product.

The neutralization stage preferably is conducted by first intimately admixing the acid stock and caustic solution in turbulent and high velocity streams Within a small mixing zone from which the resulting mixture is sprayed and atomized in finely divided form within an evacuated chamber maintained at a low absolute pressure within the range of about 9 to 88 mm. of mercury and at a corresponding water vapor temperature within a range of about 50 F. to 120 F. It is found that operating within this pressure and temperature range gives to the neutralized salt the desirable light color and purity referred to in the foregoing, and to the resulting slurry a viscosity maintainable within the range of 500 to 1500 centipoises at 100 F., contributing to the .desirably high density of the finished product.

To assure most efiicient distribution and intimacy of contact between the reactants at the point of their admixture, as within a spray nozzle, provision is made for maintaining a continuous recirculation of the slurry into the nozzle, the slurry constituting an alkali carrier as a dispersing and solubilizing medium for promoting fine particle division and reaction of the acidic and alkaline materials.

According to a preferred method of an opera.- tion, the neutralization process is started using a measured quantity of caustic solution placed in the vessel or vessels constituting, in effect, the low pressure neutralizing zone, alkali content of the solution being substantially the stoichiometrical equivalent of a measured `quantity of the acidic stock to be neutralized. At the start of and throughout neutralization cycle, the acid stock is fed at a measured rate to a stream of the caustic solution being continuously recirculated from an accumulated body in the low pressure zone to the spray nozzle, all in a manner 'such that as neutralization progresses, the caustic solution acquires increasing quantities of the neutralized salt, and the character of a slurry, while the solution or slurry continuously loses water by reason of the low pressure-induced vaporization. At all times during the neutralization however, the slurry contains reactive alkali at concentrations which are at least sufficient for complete neutralization of the acid stock. Thus, recirculation of the slurry and feeding of the acid stock continue until the entire measured quantity of the latter is taken into the neutralizer.

Thereafter, the neutralized residue may be given any further desired disposition or treatment. Preferably, I control the naturalization to produce a final slurry having a viscosity Within the indicated range, which then may be spray dried, ordinarily following addition to the slurry of suitable builders or fillers. While as previously explained, the slurry is advantageously preconditioned by the present methods to promote formation of a desirably high density spray-dried product, it is found that the quality of the product in this respect may be further improved by subjecting the slurry, and following incorporation therein of any additives, to a final deaeration at sufficiently low pressure to effect the removal of air and volatiles present in the mixture. This final deaeration of the slurry is more particularly dealt with in Patent No. 2,606,156 entitled Deaeration and Drying of Water-Soluble Sulfonated Detergent Compositions, issued August 5, 1952.

All the various features and objects of the invention, as well as the details of certain typical and illustrative procedures, will be explained to best advantage in the following description of the vaccompanying drawings, in which:

Fig. l is a flow sheet illustration of the process;

Fig. 2 is a fragmentary sectional View of the neutralizer chamber;

Fig. 3 is an enlarged fragmentary section on line 3 3 of Fig. 2; and

Fig. l is a cross-section on line 4 4 of Fig. 3.

Merely as illustrative of the derivation of the acidic hydrocarbon stock to be treated, Fig. 1 shows a preliminary sulfonation stage employing weighing tanks l0 and l I, the former containing any suitable alkane, i. e., sulfonatable or sulfatable hydrocarbon, or hydrocarbon mixtures, typically a mixture of benzenoid hydrocarbons having two or more hydrocarbon atoms, replaceable 'by sulfonation, the benzenoid radical having an attached alkyl group containing 8 to 13 car- -bon atoms. Tank i! may contain 25% solution of oleum. From the weight tanks, the alkane and acid are fed through lines l2 and I3 to the Sulfonator Il wherein the materials are subjected to suitable mixing and mechanical agitation. From the sulfonator the mixture is pumped through line l5 and the water cooled heat exchanger |6 to be reeirculated back into the sulfonator through line Il. When the sulfonation is complete, the material is pumped through lines I8 into one or the other of the holding tanks I9. The latter thus will be understood to contain a predetermined quantity of the sulfonate of known total acidity. Delivery of the sulfonate from one or the other of tanks I9 to the neutralizer, generally indicated at 20, occurs through line 2l containing the pump 22.

The neutralizing equipment in its entirety is regarded as including a closedfchamber 23 communicating through linexZl withy one-or theother of the closedpreceiver weigh tanks-2land21, the latter being' located below chamber 23 a distance atleast as great as the. height of a barometric waterleg, and-for-example about 40 feet. With chamber 23 evacuated in-theimanner already explained, andlin. communication with tanks 2.6 or 21 through line 2d, the neutralizer chamber and the yweighztank in communication therewith during: a neutralizing operation, may together be regardedas constituting the entire neutralizing zone, and chamber the low pressure part of the neutralizing zone. The solution or slurry in the chamber 23 may discharge downwardly by gravity through line 2l into the weigh tank, in which event line 24' may take the form. of a straight vertical barornetric leg. Or for such purposes as to economies in the structural or building height require-:3.v to accommodate the neutralizer equipment in a vertical' distance less than the height of a barometric leg..I may dischargethe slurry-from the. neutralizer downfinto the weigh tank by one or a series of pumps 25 in branch 24a of line 24, with branch 24h closed or eliminated. As will be understood, the displacement capacity of the pump or pumps will be sufficient for maintenance of the specified pressure conditionsin chamber 2'3.

Thesulfonatedstock is delivered from line 2l into an annular header. 28 at the top ofthe neutralizing chamber 23- andfrom which the stock is fed through branches 29to spray'heads or nozzles (typically four) generally indicated at 30, mounted in. circuiarly spacedarrangement in the head ofy the chamber. Referring to Fig. 4, each spray head comprises aY nozzle 3l threaded into an opening 32 in the chamber shell and having an inside'concave face 33 to which fluid is dischargedfrom an upperconcavity 34' in the nozzle, through opening 35. Each spray head has a body 36 threaded at 31 on the nozzle and containing al mixing chamber 38- in axial alinement with the nozzle. The sulfonate is discharged fromheader 28 throughiitting 39 and passage 4.'.1 tangentially into the chamber.

As will appear, continuously during the neutralization, a quantity of the solution or slurry contained in one or the other of tanks 26 and 2'!` in use at the. time is recirculated to the spray heads byY pump 4l through line S2 connecting with header 43. From the header, the slurry is discharged throughv branches 44, fitting 45 and passage 5.6- leading tangentially into-the mixing chamber 38, at 90 degrees fromthev sulfonate inlet passage 40. The two streams thus being discharged through the restricted passages and 46 tangentially and in the same direction within chamber 38 undergo turbulent and thorough mixing, with intimacy of contact between the reactants being. promoted by reason of the solubilizing and dispersing functions of those components of the recirculated stream in additionI tothe caustic. Sincethe rate of delivery of the recirculated stream-tol the mixing chamber 38 is desirably in volume excess over the rate of sulfonate delivery thereto, `passage 46 may be made somewhat larger than the bore 40.

Chamber 23 and the communicating receiver 2S or 21, are evacuated as by way of a head 58 connected to the shell vapor outlet 49 and communieating through duct. 50 with: theV conventionally illustrated steam ejector 5l. As. previously indicated, the absolute pressure within chamber 23 and the communicating weigh tank 6. is maintained within a range of; 9` to 88 mm. of mercury, at which pressure the temperature of the slurry becomes established in accordance with the' cooling effect of the water Vaporization withini the range of about 50 F. to 120 F. By reason of the low'pressure in the neutralizer and theform of the nozzles 3 l, the recirculated slurry components .are discharged in iinely atomized spray patterns within. chamber 23, and the resultant slurry is taken on down through line 24 into the weigh tank. Water vapor formed in the low pressure chamber is drawn off to the ejector through outlet 49, below which is mounted a bailie 49 Il to prevent spray loss.

At this point it may be mentioned that preparatory to the neutralizing circulation, a weighed quantity of solution containing caustic soda in a quantity substantially stoichiometrically'equivalent tor the sulfonate, is contained in one'of thetanks 2601' 2. At the start of neutralisation, the recirculated stream is caustic soda solution, and as neutralization continues with formation of theV sodium sulfonate salts, the caustic'solution. becomes progressively a slurry oi increasing salt concentration, until finally at the point of neutralization of all the sulfcnate charge, substantially all the caustic may have become consumed. At this stage of compiete neutralization, the slurry and tank 26. or 2i is brought within a viscosity range of from 500 to 1500 centipoises at F.

The following is a tabulation of data in a typical run:

TableI Alkane in tank 10 10.000 1bs. 25% Oleuin in tank 11 10,775 lbs. 25.40 Baume caustic soda solution 39,230 lbs.

(19.5%) in receiver 26 or 27. Acid addition time to sulfonator 1.4 hrs. S5 min. Maximum temperature during acid 93 F.

addition' to sulfonator.

Maximum temperature duringdiges- 94 F.

tion in suli'onator.

Time of sulfonic acid delivery to 12 hrs. 25 min;

neutralizer.

Total potential amount of water 35,0001bs.

available.

Total water remove'd'by evaporation 4,400 lbs.

Average flow rate of sulfonic acid to 2.5 gal. per min. neutralizer;

Approximate recirculation rate of 40 to S0 gal. per

vcausticand slurry. min. Neutralizer chamber temperatu1e 90 F. to 120 F. Vacuum chamber absolute pressure-- 12 to 31 mm. mercury.

The slurry produced was found to have ape proximately the following analysis:

Viscosity at 100.7 F. c. p 900 Considering now further treatment of the slurry, following completion of the neutralization cycle, the slurry is'taken from tank; 2d or 2'5 by way of line 55 and is discharged by pump 55 through line 51 into an appropriate E3, whereinv there may be added to the slurry any suitable builder or builders (such as soda ash, sodium bicarbonate, alkali metal silicate, borax, alkali metal phosphate, sodium citrate or sodium carboxy methyl.v cellulose), together with any of the usual fillers (such as sodium sulfate, sodirun chloride, fullersearth or'silica). As illustrative, theymixer 38k is shown torhave an additive inlet 5:9and to contain asuitable agitator 68. During themixing, air is introduced to and retained by the mixture in` quantities tending to lower the density of the nal spray dried product below the higher density desired for the active concentration of the product.

This condition is cured by discharging the mixture by pump BI through line E2 into a deaerator 63 comprising an enlarged chamber evacuated through line eli to maintain within the chamber an absolute pressure within the range of about from 50 to 250 mm. of mercury. The mixture is discharged into the chamber through an appropriate spray head 95 so that the materials become iinely dispersed and therefore efficiently deaerated in the low pressure atmosphere. From the deaerator, the slurry is discharged by pump 56 through line 6l into a spray drier 69, for example of the type shown in my Patent No. 2,555,515 on Spray Drier, issued June 5, 1951. In the drier the slurry is air-dispersed and dehydrated to form a finished granular product continuously discharged at 59 from the bottom of the drier.

I claim:

1. The method of neutralizing an acidic stock of the class consisting of sulfonated and sulfated organic compounds having an aliphatic radical containing between about 8 to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes converting said stock to a slurry of a water dispersable alkali metal salt thereof by [discharging a mixture] introducing separated streams of said stock and an aqueous solution of an alkali metal hydroxide into a plurality of small chambers wherein the streams are intimately admired while flowing at high velocity, then spraying the mired materials in finely divided form openly and through an extended path within the atmosphere oi a cone maintained at an absolute pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 F., limiting dehydration of the mixture to produce a owable slurry, and flowing the slurry from said zone.

2. The method of neutralizing an acidic stock of the class consisting of sulfonated and sulfated organic compounds having an aliphatic radical containing between about` 8 to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes converting at an absolute pressure between about 9 to 88 mm. of

mercury and at a temperature between about 50 F. to 120 F. said stock in an aqueous mixture to a water dispersable alkali metal salt thereof contained in a owable slurry by [discharging a mixture] introducing separated streams of said stock and an aqueous solution of an alkali metal hydroxide into a plurality of small chambers wherein the streams are intimately admixed while flowing at high velocity, then spraying the mixed materials in nely divided form openly through an extended path within the atmosphere of a zone maintained under said pressure and free falling from the locus of spraying to a collection body of the slurry in the lower portion of said zone, limiting dehydration of the mixture to produce a owable slurry, and continuously flowing the slurry from said zone during its formation.

3'; The method of neutralizing an acidic stock of the class consisting of sulfonated and sulfated organic compounds having an aliphatic radical containing between about 8 to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes converting at an absolute pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 F. said stock in an aqueous mixture to a water dispersable alkali metal salt thereof contained in a 'lowable slurry having at 100 F. a viscosity between about 500 to 1500 centipoises by [discharging a mixture] introducing separated streams of said stock and an aqueous solution of an alkali metal hydroxide into a plu-'- rality of small chambers wherein the streams are intimately admired while flowing at high 'uelocity, thenspraying the mixed materials in finely divided form openly and through an extended path within the atmosphere [at] of a zone maintained under said pressure, limiting dehydration of the mixture to produce a flowable slurry, and continuously flowing the slurry from said Zone during its formation.

4, The method of neutralizing an acidicY stock of the class consisting of sulionated and sulfated organic compounds having an aliphatic radical containing between about 8 to 18 carbon atoms and the-alkali metal salts of which have detergen properties, that includes [discharging a stream] introducing separated streams of said stock together with an aqueous alkali metal hydroxide solution into a plurality of small chambers wherein the streams are intimately admixed while flowing at high yelOcity, then spraying the mired materials into a zone maintained at a subatmospheric pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 F. wherein the resulting mixture is cooled 'by water vaporization from the mixture caused by the low pressure in the zone, limiting dehydration of the mixture to produce a lowable slurry, recirculating an aqueous slurry of reacted stock and alkali from said zone into said stream of the stock being discharged into said zone and flowing the product slurry from said zone.

5. The method of neutralizing an acidic stock of the class consisting of sulfonated and sulfated organic compounds having an aliphatic radical containing between 8 to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes [spraying a stream] introducing separated streams of said stock [together with] and an aqueous alkali metal hydroxide solution into a plurality of small chambers wherein the streams are intimately admired while flowing at high velocity, then spraying the mixed materials openly and in free falling dispersion within a zone maintained at a subatmospheric pressure wherein the resulting mixture is cooled by water vaporization from'the mixture caused by the low pressure in the zone, the mixture being maintained in said Zone at an absolute pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 F., repeatedly and continuously recirculating an aqueous slurry of reacted stock and alkali from said zone into said stream of the stock and throughout the period of its sprayed injection into said zone, and continuously depleting the water content of the recirculated slurry by the low pressure induced water vaporization to produce a flowable and pumpable slurry.

`6. The method of neutralizing a quantity of an acidic stock of the class consisting of detergent-forming sulonated and sulfated organic compounds having an aliphatic radical containing between 8 to 18 carbon atoms with an adueous solution of a substantially stoichiometrical quantity of an alkali metal hydroxide, that includes maintaining said alkali solution in a low lcarri pressure zone, continuously evacuating saidzone and maintaining therein a pressure between about 9 to 88 mm. of mercury and an essentially water vapor atmosphere having a temperature between about 50 F. to 120 F., continuously injecting [a stream of] separate streams of said solution and said stoel; into a plurality of relatively small mixing llzone] chambers and then immediately in spray form into said low pressure zone, continuously recircuiating said alkali solution together with neutralized acidic compounds irom said low pressure zone into said mixing [zone] chambers substantially throughout injection of said stock into the zone miring chambers so that the all ali solution and neutralized compound are intimately mixed with the stock and immediately sprayed therewith into the low pressure zone and the recirculation is continued until all the acidic stock is neutralized, limiting dehydration oi the mixture to produce a tlowable slurry, and flowing the slurry from said zone.

'1. The method of neutralizing an acidic detergent-forming stock composed predominately of a mixture of benzenoid hydrocarbons in which the benzenoid radical has an attached alkyl group containing between 8 to 1S carbon atoms and has at least one hydrogen atom replaced by an -OSO2OH radical, that includes converting said stock to a slurry of a water dispersable alkali metal salt thereof by [discharging a mixture] introducing separated streams of said stock and an aqueous solution of an alkali metal hydroxide into a plurality of small chambers wherein the streams are intimately admired while flowing at high velocity, then spraying the mixed materials in nely divided form openly and through an extended path within the atmosphere of a zone maintained at an absolute pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 limiting dehydration of the mixture to produce a flowable slurry, and tlowing the slurry from said zone.

8. The method of neutralizing with a quantity of an alkali metal hydroxide a substantially stoichiometrical quantity of an acidic detergentforming stock composed predominately of a mixture of benzenoid hydrocarbons in which the benzenoid radical has an attached alkyl group containing between 8 to 18 carbon atoms and has at least on hydrogen atom replaced by an --OSOzOI-I radical, that includes maintaining said alkali solution in a lower collecting zone, continuously injecting Ea stream] separate streams of said stock into a plurality of relatively small mixing [zone] chambers and then immediately in spray form into an enlarged low pressure neutralizing zone above the collecting zone and from which the sprayed material passes into the collecting zone, continuously recirculating said alkali solution together with neutralized stock from said collecting zone into said mixing [zone] chambers substantially throughout spraying of said stock into the zone so that the recirculated alkali and neutralized stock are intimately mixed with and in larger quantity than the stock and immediately sprayed therewith into the low pressure zone, continuously evacuating said neutralizing zone and maintaining the material therein at a pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 F., continuously depleting said slurry of its water content by virtue of the existent pressure to produce a lowable slurry having a viscosity at F. between about 500 to 1500 centipoises, and continuously flowing said slurry from said neutralizing zone downwardly into the collecting zone.

9. The method of producing a detergent product from a base stock of the class consisting of sulonated and sulfated organic compounds having an aliphatic radical containing between about 8 to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes converting said stock to an aqueous slurry of a water dispersable alkali metal salt of the stock by discharging a mixture of said stock and an aqueous solution oi" an alkali metal hydroxide in finely divided orrn openly and through an extended path within the atmosphere oi a zone maintained at an absolute pressure between about 9 to 58 mm. o mercury and at a temperature between about 50 F. to 120 limiting dehydration of the mixture to produce a flowable slurry, mixing solid additives with the slurry, deaerating the resulting mixture at subatmospheric pressure, and spray drying the deaerated mixture.

10. The method of producing a detergent product from a base stocii of the class consisting oi suli'onated and suii'ated organic compounds naving an aliphatic radical containing between .to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes converting said stool; to an aqueous slurry oi' a water dispersable alkali metal sait or the stock by ispraylng a mixture] introducing separated streams or' said stock and an aqueous solution oi' an alkali metal hydroxide mrc a praralzly of small' chamoers wherein the streams are mtimately admired while l'owmg at high lvelocity, their. spraying the miredl materials in i'inely divided iorm openly and through an extended path within the atmosphere ol' a zone maintained at an absolute pressure between about 9 to dal mm. of mercury and at a temperature between about 50 F. to 120 F., limiting dehydration or the mixture to produce a Ilowable slurry, mixing solid additives with the slurry, deaeratirig Une resulting mixture at an absolute pressure between about 5u to Z50 mm. o1' mercury, and spray drying trie oeaerated mixture.

11. rEhe method or neutralizing an acidic stock of the class consisting or suiionated and suitated organic compounds having an aliphatic radical containing between about c to ie carbon atoms and the ailsaii metal salts oi' which have detergent properties, that includes converting said stock to a slurry oi' a water dispersaoie alkali metal salt thereof by spraying a niiXtui-ej imroaucmy separated streams oi said stoel; and an aqueous solution o1` an alkali metal hydroxide into a plurality of small chamoers wherein the streams are lmlmately admired while Jlowmg at high velocity, thea spraying the mixed materials in finely divided i'orm openly and through an extended path within the atmosphere oi" a zone maintained at an absolute pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 F., limiting dehydration of the mixture to produce a nowable slurry, flowing the slurry into a drying zone and therein spray drying the slurry to produce a granular product.

12. The method of neutralizing an acidic detergent-forming stock composed predominately of a mixture of benzenoid hydrocarbons in which the benzenoid radical has an attached alkyl group containing between 8 to 18 carbon atoms and has at least one hydrogen atom replaced by an -OSOzOH radical, that includes converting said stock to a slurry of a water dispersable alkali metal salt thereof by [discharging a mixture] introducing separated streams of said stock and an aqueous solution of an alkali metal hydroxide into a plurality of small chambers wherein the streams are intimately admired while flowing at high velocity, then spraying the mixed materials in finely divided form openly and through an extended path within the atmosphere of a zone maintained at an absolute pressure between about 9 to 88 mm. of mercury and at a, temperature between about 50 F. to 120 F., limiting dehydration of the mixture to produce a fiowable slurry, mixing a solid additive with the slurry, and spray drying the resulting mixture.

13. The method of neutralizing an acidic stock of the class consisting of sulfonated and sulfated organic compounds having an aliphatic radical containing between about 8 to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes converting said stock to a slurry of a water dispersable alkali metal salt thereof by [intimately mixing] introducing separate streams of the acidic stock and an aqueous alkali metal hydrovide [solution in a. turbulent and high velocity stream within a] tangentially into each of a plurality of circular and relatively small mixing [zone] chambers, then suddenly discharging the high velocity mixture axially from the chambers in finely divided form openly and through an extended path within the atmosphere of an enlarged zone maintained at an absolute pressure between about 9 to 88 mm. of mercury and at a temperature between about 50 F. to 120 F. at which the mixture particles undergo cooling by virtue of water vaporization therefrom induced by the 10W pressure, limiting dehydration of the mixture in said zone to produce a owable slurry, and ilowing the slurry from said zone.

ALAN C. STONEMAN References Cited in the le of this patent or the original patenlt UNITED STATES PATENTS Number Name Date 1,968,797 Bertsch July 31, 1934 2,162,269 Mikeska June 13, 1939 2,187,244 Mills Jan. 16, 1940 2,205,037 Henke June 18, 1940 2,316,670 Colgate et al Apr. 13, 1943 FOREIGN PATENTS Number Country Date 661,130 Great Britain Nov. 14, 1951 

